Abstract
To achieve a high seismic stability of a newly proposed bridge type, called the GRS integral bridge, a high tensile resistance of reinforcement layers at the back of the facing is crucial. This resistance is the minimum of the connection strength between the reinforcement and the facing, the tensile rupture strength of reinforcement and the pull-out resistance of reinforcement. To evaluate the pull-out resistance of a rough phosphor bronze grid used in the model shaking table tests performed to evaluate the seismic stability of GRS bridge in comparison with those of other types of grid reinforcements including polymer grids, a series of pull-out tests were performed on these various types of reinforcement embedded in Toyoura sand under different vertical confining pressures. The pull-out resistance increases with an increase in: 1) the covering ratio and surface roughness of the longitudinal members of grid; and 2) the thickness of transversal members of grid. The peak resistance by the surface friction (factor 1) tends to be mobilized earlier than the passive pressure resistance (factor 2). The reinforcement used in the model shaking table tests has a resistance much lower than the largest one among those measured in the pull-out tests.
